Apparatus for heating liquids.



PATENTED AUG. 22, 1905.

H. JUNKERS. APPARATUS FORRHBATING LIQUIDS.

APPLIUATION FILED JULY 17, 1902.

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' H. JUNKERS. APPARATUS FOR HEATING LIQUIDS.

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APPLICATION FILED JULY 17.1902.

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UNITED STATES PATENT OFFICE.

APPARATUS FOR HEATING LIQUIDS.

Specification of Letters Patent.

Patented Aug. 22, 1905.

Application filed Tuly 17, 1902. Serial No. 115,998.

To all whom it may concern,.-

Be it known that I, HUGO JUNKERS, a subject of the German Emperor,residing at Aachen, Germany, have invented certain new and usefulImprovements in Apparatus for Heating Liquids, of which the following isa specification.

This invention has for its object to improve the interchangevof heatbetween gaseous and liquid heat-carriersfor example, `heating gas andwater-by causing the heating-gas to give up its heat through metalplates which divide the cross-section of the passage for the heating-gasinto thin layers which give up the heat well and as completely aspossible. The heating-gases on their part are compelled. to pass throughthe whole of the cross-section of their flue or passage, which isdivided into thin layers by the plates. They thus give up the heat tothe metal plates, which conduct the heat on both sides to the shells orwalls of the water-space of the apparatus, from which it is given up tothe water. This new arrangement is based on the known experimental factthat the transfer of heat from gaseous substances to metal is much worsethan that from metal to liquids-for example, water-and, further, thatgaseous substances give up their heat better accordingly as the layersof heating-gas are thinner. From this it follows that for the taking upof any given amount of heat from heating-gases a very much largerheating-surface is preferably arranged than for the giving up of thesame amount of heat from a heating-surface to a liquid. The metal-plateheating-surface arranged in the cross-section of the flue or passage forthe heating-gas fulfils this requirement in every case. The metal platesact on both sides, since they take up the heat on both surfaces. Theheating-surface is therefore inexpensive. They, moreover, divide thewhole cross-section of the fiue for the heating-gas into passages in theform of thin layers, these passages being preferably of equal orapproximately equal length and width. The heating-gases therefore giveup their heat very completely.

In the accompanying drawings a number of examples of heating apparatusof this kind are shown.

Figure 1 is a vertical section on the line C D, Fig. 2, and Fig. 2 ahorizontal section on the line A B, Fig'. 1. Fig. 3 is a verticalsection on the line G H, Fig. 4, and Fig. 4 a

horizontal section on the line E F, Fig. 3. Fig. 5 is a vertical sectionon the line L M, Fig. 6, and Fig. 6 a horizontal section on the line IK, Fig. 5. Fig. 7 is a vertical section on the line P Q, Fig. 8, andFig. 8 is a horizontal section on the lineN O, Fig. 7 Figs. 9 and 10show a modification in vertical central section and cross-section,respectively. Fig. 11 is a vertical section on the line X Y, Fig. 12,and Fig. 12 a horizontal section on the line V W, Fig. 11. Fig. 13 isavertical central section, and Fig. 141 a horizontal section on the lineZ Z, Fig. 13. The above pairs of figures respectively show various formsof my improved apparatus. Figs. 15, 16, 17, and 18 arel horizontalsections illustrating further modified forms of my improved apparatus.Figs. 19 to 22 show various forms of heat-conducting plates.

In the arrangements shown in Figs. 1, 2, 3, 4, 7, 8, 9, 10, 11, and 12the water enters the cylindrical' casing at a and passes throughsuitably-divided chambers into the draw-off chamber c and leaves thisthrough the pipe CZ. In Figs. 5, 6, 13, and 141 the chambers .7) areomitted, since no special draw-0E chamber is provided. In Figs. 7 and 8,by way of example, two systems of plate-heating bodies are arrangedconcentrically to each other. The heating takes place, for example,bymeans of gas in the burner e. The heating-gases are drawn by the draftthrough the heater, which is divided by the metal plates into thinpassages, and give up their heat to the two surfaces of the plates. Theplates themselves conduct the heat toward both ends, in a direction atright angles to the current of heatinggas, to the walls f, limiting thewater-space, and these walls finally give up theheat to the water. Theplates can be flat, see Figs. 2 (I), 3, 4 (I), 5, 6, 7, 8, 11 (II), 12(II); suitably curved, for example, cylindrically, see Figs. 1, 2 (II),9, 10; conical, see Figs. 11 (I) and 12 (I); involute-shaped, Fig.4(11); and also of such form that they are connected at both ends to thesame layer of Water, see Figs. 13, 14 (I, II, III), 15, and 16. Thedivision of the cross-section of the heating-gas flue by plates whichare curved in involuteshaped lines has the object of making the severallayers of equal width at every place. The construction shown in Fig. 16is obtained from that shown in Fig. 15 by making the intermediate spacesai equal to zero. The position of the plates can be horizontal,

Athe vessel, Figs. 17 and 18.

vertical, or inclined at any desired angle. The form of the plates canbe varied in two directions: First, in the direction of the current ofheating-gas. In the heater, by reason of the giving up of the heat ofthe heating-gases tol the metal-plates, a continuous decrease takesplace in the temperature of the said gases. Accordingly, the differenceof temperatures between the heating-gases and the liquid also decreases.Account can be taken of this circumstance by altering the thickness ofthe ythe plates of the other sections, as may appear desirable in viewof the production of draft and advantageous construction. Second, it maybe advantageous to vary the thickness of the plates in the direction ofthe current or flow of heat at right angles to the current or flow ofthe heating-gas. This may be eX- plained as follows: The reception ofheat at the plates takes place on both sides over the whole surface. Theiiowing away of the heat in the plates themselves takes place from themiddle toward both ends. With a given fall of temperature between themiddle of the plate and the liquid-wall the amount of metal used is thesmallest when the thickness of the plate increases from the middletoward the walls of Finally, the current of heating-gas can be conductedthrough the apparatus in such a manner that it rises in the spaces x,Fig. 15, and descends in the spaces y, so that the plates are acted uponon one side by the hottest and on the other side by the cooler gases.

Experience -has shown that in the heating -by the hot gases of theplates connected at the two long sides to the walls cooled by theVliquid the said plates expand longitudinally and transversely.` Thetemperature of the plates is highest at the place where the hot gasesenter and decreases from there both in the direction of the lengthA ofthe plate and also toward both sides from the middle line. Accordingly,the transverse expansion is the greatest at the inlet of theheating-gases and the longitudinal expansion the greatest in the middleline. The expansion caused by the heating of the plates can actinjuriously in two directions, according to the magnitude lof thedifference of temperatures: First, by

the expansion in the direction of the breadth of the plates either thewalls inclosing the liquid are pressed in or in the event of the saidwalls not being capable of yielding the plates must assume an undulatingform. With intermittent working leakage is liable to be caused by thisexpansion. Second, by the expansion of the plates in a longitudinaldirection a shearing stress is liable to be set up in thecontact-surfaces between the hot plates and the cool walls inclosing theliquid in such a manner that the metallic connection between the twoparts is broken andthe plates are torn away from the said walls. Simplemeans have already been given above for rendering harmless the thermalexpansion. They consist in curving the plates in the direction of theirbreadth, so that they can yield elastically, and in arranging a numberof systems of short plates behind each other in the longitudinaldirection, so that the longitudinal expansion can cause noappreciableharm. The thermal expansion can also be rendered harmless bysuitably-arranged cuts or slits. In order to render harmless theexpansion of the plates less the expansion of the plates in thelongitudinal direction, the plates can be also slit transversely to thisdirection of expansion, as in Fig. 20, so that the plates themselves mayconsist of comb -like plates having a greater or less number of slits,the` separate parts of which can yield freely to the thermal expansionand not endanger the metallic connection of the plates with the wallsinclosing the water. The distribution, the length, and the thickness ofthese plates are preferably made similar to the unslit plates. Thetransverse slits of the slit metal plates can also be provided with onedeflecting edge, Fig. 21, or with two deflecting edges, Fig. 22, so thatthe heatinggases passing through are thrown into eddies.

What I claim isl. An apparatus for heating liquids, comprising shells orwalls in contact on one side with the liquid and on the other side withthe heating-gases, and metal plates connected at both ends to the sidesof said shells or walls in contact with the heating-gases, said platesincreasing in thickness from the middle toward their ends, and beingarranged at short distances apart, substantially as, and for thepurposes, specified.

2. An apparatus for heating liquids, com- `prising shells or walls incontact on one side with the liquid and on the other side with theheating gases, and independent groups of metal plates, which plates areconnected to the sides of the said shells or walls in contact with theheating-gases and are arranged at short distances apart, substantiallyas, and for'the purposes, hereinbefore described.

slits and connected to the sides of said shells or walls in contact withthe heating-gases, said plates being arranged at short distances apart,substantially as described.

4. An apparatus for heating liquids, comprising shells or walls incontact on one side with the liquid and on the other side with theheating-gases, and metal plates connected to the sides of said shells orwalls in contact with the heating-gases, said plates being provided withslits having laterally-turned edges, substantially as, and for thepurpose, hereinbefore described.

5. A liquid-heater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heatinggases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole crosssection of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively.

6. A liquid -heater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heatinggases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole crosssection of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively, saidplates contacting' with the water-cooledwalls with one side or edgeonly.

7. A liquid heater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heatinggases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole crosssection of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively, saidplates having their sides contacting with the water-cooled walls.

8. A liquid -heater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heating-gases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged v close together, divide the whole cross-section of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to theliquid, respectively, saidplates contacting with the water-cooled walls, and said platesincreasing in thickness toward the water-cooled walls.

9. A liquidheater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heating-gases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole cross-section of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively, andsaid plates curved to form cylindrical or conical surfaces.

l0. A liquid-heater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heatinggases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole crosssection of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively, andsaid plates forming independent groups behind each other.

11. A liquid-heater, consisting of hollow walls which are in contact onone side with the liquid and on the other with the heatinggases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole crosssection of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively, andsaid plates provided with suitable slits.

12. A liquid-heater consisting of hollow walls which are in contact onone side with the liquid and on the other with the heatinggases and inwhich the heating-surfaces are formed exclusively of metal plates which,arranged close together, divide the whole crosssection of theheating-gases into thin layers through which the heating-gases must passuniformly, while the plates take up the heat on both surfaces and giveit up to the walls of the vessel and to the liquid, respectively, saidplates provided with suitable slits, and having bent edges in the slits.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

HUGO JUNKERS.

Vitnesses:

PETER LIEBER, WM. Ess ENWEIN.

